Boring mill



July 20, 1948. o. E. SCHURR BORING MILL Filed March 12, 1945 3 Sheets-Sheet 1 INV ENTOR OTTO E. SCHUIZE BYMZM ATTORNEYS July 20, 1948.-

o. E. SCHURR 503mg MILL 3 Sheets-Sheet 3 Filed March 12, 1945 INVENTOR OTTO E. SQHURR WAZQLQV ATTORNEYS Patented July 20, 1948 2,445,4e7 BORING MILL Otto E. Schurr, Hamilton, Ohio, assignor, by mesne assignments, to Lima-Hamilton Corporation, Hamilton, Ohio, a corporation oi Vire ginia Application March 12, 1945, Serial No. 582,243

11 Claims. (01. 77-4) This invention relates to boring mills.

An object of the invention is to provide an improved construction of a supporting and driving mechanism for a rotating table of a boring mill, with particular regard to improved means for chuck and releasing the work piece on the work table of the machine.

Another object of the invention is to provide a table for a boring mill that is supported for rotation independently of the mechanism that drives the table.

Still another object of the invention is to provide a table construction for a boring mill wherein the table is supported for rotation independently of the spindle for the table, whereby the spindle is not required to carry the thrust of the table.

Still another object of the invention is to provide a table for a boring mill and a driving mechanism for the same wherein the table and the driving mechanism are independently supported to relieve the thrust load of one from the other, and mechanical means is provided for operably connecting the driving mechanism to the table for driving the same without causing any transmission of the thrust load of one member to the other.

Still another object of the invention is to provide an improved lubrication system for the driving mechanism and the table of a boring mill constructed in accordance with any of the foregoing objects,

Further objects and advantages will become apparent from the drawings and the following description:

Figure 1 is a vertical cross-sectional view through the table and the driving mechanism for the same.

Figure 2 is a horizontal cross-sectional view of the table and the driving mechanism taken along line 2-2 of Figure 1.

Figure 3 is a horizontal cross-sectional view, a-

part of the view being shown in elevation, taken along line 3-3 of Figure 1.

Figure 4 is a cross-sectional view of the clutch jaw arrangement taken along line 4-4 of Figure 1.

In this invention, the boring mill has a main frame In that has a chamber II in which there is located a suitable driving mechanism and power source for drivingthe drive shaft 12. The drive shaft 12 is supportedin the taper roller bearing 13 that is carried in a sleeve 14 supported in the wall i of the main frame 10.

The main frame is provided with a vertically arranged spindle bearing 15 that receives a sleeve bearing 11 adjustably positioned therein. The sleeve bearing [1 is provided with a tapered bearing surface l8 that is adapted to'receive a correspondingly tapered bearing surface on a spindle journal 19 that is keyed t0 the table 20 of the boring mill. The spindle journal 19 is prevented from upward movement in the bearing sleeve 11 by a thrust member 13.

The table 20 of the boring mill is carried upon a plurality of bearing pads 21 that are positioned radially of the spindle bearing 16 upon the horizontal wall 22 of the frame l0. A bearing ring 23 is secured to the under-side of the table 23 by means of bolts or cap screws 24 suitably spaced around the bearin ring 23. The bearing ring 23 directly supports the table 20 upon the bearing pads 21 so that the table 20 is carried directly upon the main frame 10 of the boring mill. The table 20 is provided with a passage H5 through which cutting fluid can drain from the table and pass through the hollow interior of the spindle 19.

The table 20 supports a plurality of chuck jaws 25 each of which is slidably supported and guided upon suitable radially positioned guide rails 23 that cooperate with the chuck jaws 25 to guide them in a true radial movement relative to the axis of the spindle journal l9. Each of the chuck jaws 25 is carried on a T-shaped member that is slidably retained in the T-shaped guide rails 25. A T-headed bolt 101 extends upwardly from the T-slot I02 inthe member I00 through the clutch jaw 25, a nut I03 being on the end of thebolt iii to secure the chuck jaw 25 to the member Hill. A serrated joint between the member 100 and the chuck jaw 25 permits radial adjustment of the jaw upon the member I00. A ring 21 is positioned beneath the ledges 33 on the table 20 and is supported in this position by means of an annular plate 29 secured to the underside of the table 20 by means of the bolts 30 suitably spaced around the annular plate 23. The ring 21 is prevented from upward vertical movement by means'of the ledges 33 positioned radially around the ring 21 extending from the table 20, thus retaining the ring 21 between the ledges 33 and the supporting I plate 29.

A spindle 3| is carried by each of the chuck jaws 25, each chuck jaw being secured to a spindle 31 by means of bolt 32. The spindles 31 are journaled in bearing sleeves 28 carried in cam slots I05 provided in the ring 21, the cam slots I05 providing for radial movement of the chuck jaws 25 upon rotation of the ring 21. j

The chuck jaws 25 are adapted toreceive and support the work-piece, such as the car wheel 35 that is positioned on the table 20 of the boring mill to have the bore thereof finished by means of the boring tool 36.

The driving mechanism for the table 20 consists of a ring gear 31 that is supported upon a bearing member 38 having a vertical sleeve portion 39 upon which the ring gear 31 is journaled and an annular flange portion 40 that is engaged by the lower wall of the ring gear 31 to support t e same and take the downward thrust of the 3 rin gear 31. The bearing member 36 for the ring gear 31 is carried on the main frame of the boring mill and is co-axial with the spindle journal l9 of the table 20.

The ring gear 31 is driven by a pinion 4| carried upon the drive shaft l2 and keyed thereto by means of the key 42.

The ring gear 31 carries a, vertically positioned driving lug 45 that extends into a recess 46 provided in the ring 21. The recess 46 is considerably longer than the driving lug 45, as shown in Fig. 2, so that the driving lug 45 can apply an initial bump to the ring 21 when disengaging the chuck jaws 25 from the car wheel 35 in a manner hereinafter described. The plate 29 is provided with an opening 41 through which the drivin lug 45 extends into the recess 46 provided in the ring 21, the opening 41 being at least equal in length to the travel of the spindle 3| in the slot I plus the travel of the lug 45 in the recess 46 to permit freedom of movement or lost motion of the driving lug 45 longitudinally in the recess 46 and move the spindle 3| throughout its stroke of movement in the slot I00.

Driving of the table 20 thus takes place from the pinion 4| through the ring gear 31, and from the ring gear 31 through the driving lug 45 driving the ring 21, and from the ring 21 through the chuck jaws 25to the work-piece or car wheel 35, the table 20 being normally held stationary until the chuck jaws 25 engage the car wheel 35-to rotate the same, in a manner hereinafter described.

The ring gear 31 rotates within an annular chamber 50 provided by the wall of the frame l0 of the boring mill. The wall 5| forming the annular chamber 50 is provided with a portion 52 in which the pinion 4| rotates. The upper edge 53 of the wall 5| cooperates with the lower edge 54 of the table 20 to form a tortuous passage 55 therebetween that effectively prevents oil in the chamber 50 from seeping therefrom when the oil is agitated during the rotation of the table 20 and the ring gear 31.

A chamber 56 is provided by the wall of the frame l0 in which the bearing pads 2| that support the table 20 are located. The chamber 56 is adapted to be filled with oil for lubricating the bearing surfaces between the bearing pads 2| and the bearing ring 23.

Lubricating oil is supplied to the chambers 50 and 56 from a suitable source of pressure supply through an oil inlet passage 51 that is provided in the lower end of the bearing journal l6. The oil passage 51 communicates with an annular groove 58 provided in the support member 59 for the bearing sleeve |1 that is secured to the lower end of the bearing journal |6 by means of the bolts 60'. The annular groove 58 communicates with an annular chamber 6| through means of the bored passageways 62 to thereby supply oil under pressure into the passage 63 provided in the bearing journal l6 that empties the oil into the chamber 56. From the chamber 56, the oil overflows the upper edge 64 of the chamber 56 into the passageways H0 and I so that oil is delivered into the chamber 65 for lubricating the pinion 4|, the pinion 4| carrying oil into engagement with the ring gear 31. The oil then flows from the chamber 65 into the main gear chamber ll of the boring mill through the taper bearing l3 for the drive shaft 12, and excess oil overflows from the chamber 65 through the opening I 2 in the frame wall l0.

The bearing surface between the r g 63 3'! and the bearing member 38 for the same is lubricated by oil flowing from the chamber 56 through suitable passages 66 provided in the upper edge 64 of the chamber 56, the passages 66 communicating with grooves 61 provided in the bearing surface of the ring gear 31.

A braking mechanism is provided to stop rotation of the table when a boring operation has been completed and this braking mechanism consists of a brake drum 10 that is secured to a support member 1| attached to the lower end of the spindle journal I 6 by means of the bolts 12. An oil seal 14 is provided between the brake support member 1| and the support member 59 for the bearing sleeve H to prevent lubricant passing therebetween and thereby keep the brake drums 10 free of oil.

The brake drum 10 is enclosed by a brake-band 15 that has one end thereof mounted upon the frame III by means of the mounting device 16. The opposite end of the brake-band 15 carries a lug 11 through which there extends a pin 16 surrounded by a spring 19 that normally retains the brake-band 15 in an extended or released condition.

The pin 16 is moved in a rightward direction against the action of the spring 19 by means of an actuating arm 80 as pivotally mounted on a pin 6| and has a suitable cam-operating mechanism on the end thereof for operating the pin 16 to draw the same in a rightward direction as viewed in Fig, 3 when the arm 60 is moved in a leftward direction.

The brake-operating mechanism consists of a hydraulically actuated piston cylinder arrangement that is composed of the cylinder 8| suitably attached to the frame ID of the machine by means of the bolts 62. The cylinder 6| has a cylinder bore 63 that receives a hollow piston 84 having one end thereof closed by means of a closure plate 85, see Fig. 1. A spring 86 secured between the closure plate 65 and the end wall 81 for the cylinder 8| normally holds the piston 84 in the position illustrated in Fig. 1.

The interior of the piston 64 is filled with fluid under pressure through a supply line 68 that is connected to a pump 89 driven by an electric motor 90. The pump 69 receives a supply of fluid from the reservoir 9| for delivery into the hollow interior of the piston 84 upon operation of the pump, and to which the fluid is returned through the line 88 when the spring 86 returns the piston 64 to the position illustrated in Fig. 1 after operation thereof. The pump 89 may be of the centrifugal type that allows a return flow of the fluid through the pump whenever the pump is not operating, or any other suitable pump that will allow this flow, can be used for this purpose.

The tapered bearing surfaces of the bearing sleeve l1 and the spindle journal l9 provide for a take-up of bearing wear between these surfaces. The bearing sleeve I1 is threadedly received into the support member 59, and under normal circumstances is retained from rotation by means of a key 9|a that engages a. key slot 92 provided in the outer wall of the bearing sleeve H. The key 9|.a is secured in position in the journal housing l6 by means of the bolt 93. Rotation of the support member 59 in one direction or the other will cause movement of the bearing sleeve |1 upwardly or downwardly to thereby compensate for any wear occasioned between the bearing surface of the sleeve l1 and the spindle journal I9.

From the foregoing description, it will be ap- Pa that each of the major elements of the Operation When a car wheel is to have the bore thereof I finished by the machine of this invention, the

car wheel is placed upon the chuck jaws 25 in the manner illustrated in Figure 1. When the chuck jaws 25 are in open position, the spindles 3| will be positioned in the opposite ends of the arcuately-shaped slots |a provided in the ring 21 as illustrated in Figure 2. The bearing sleeves 26 containing the spindle members 3| are slidable in the slots |0|Ja from end to end thereof. The slots |00a are generally cam-shaped in contour so that the spindle sleeves 28 move from end to end in the slots llllla. The jaws 25 connected to the spindles 3| thus move inwardly and outwardly relative to the work-piece or car wheel 35 to engage or disengage the same.

Also, when the chuck jaws are in open position,'the driving lug 45 is in the opposite position in the recess 46 from that illustrated in Figure 2, which is accomplished by applying the brake and operating the drive to the lost motion connection in reverse direction.

With the car wheel 35 supported upon the chuck jaws 25, the drive shaft l2- through the pinion 4| drives the ring gear 31. The ring gear 31 is driven slowly, preferably with the brake applied to effect tight clamping of the work, until the driving lug 45 engages the end of the recess 46 with a bumping action as illustrated in Figure 2. On the happening of this event, the ring 2'! is rotated relative to the table 26, the table 20 remaining stationary due to its own weight and the weight of the car wheel resting thereuponv and with the application of the brake. Rotation of the ring 21 in a counter-clockwise direction, as viewed in Figure 2, causes the spindles 3| to move radially inwardly toward the axis of the table 20, as produced by the cam-shape of the slots "Illa. This operation continues until the chuck jaws 25 engage and clamp upon the periphery,

of the car wheel 35, whereupon the movement of the chuck jaws is halted and the structure including the car wheel, the chuck jaws and the table 20 becomes a rigid structure that rotates together as driven through the ring '21 by means of the driving lug 45 from the ring gear 31.

After the chuck jaws solidly engage the car wheel 35 and the brake is released, the speed of the table 20 can then be increased to normal working speed, and the boring tool 36 may then be passed through the wheel for boring the same.

When the boring operation iscomplete, the current to the driving motor for the machine is turned off. The pump 89 is then operated by the electric motor 90 to supply fluid under pressure through the supply line 68 into the hollow interior of the piston 84 thereby advancing the same to the left to cause clockwise movement of the arm 80 and thereby bind the brake-band I upon the brake drum '10 to stop rotation of the table 20 I2 is then driven in a reverse direction, with the brake applied, thereby rotating the driving lug 45 in a clockwise rotation until the driving lug 45 strikes the opposite end of the recess 46. The initial momentum given the ring gear upon this reversal of rotation is sufllcient to cause the driving lug 45 to apply asharp bump upon the end of the recess 46 to release the jaws 25 from the car wheel and begin clockwise rotation of the ring 21, and thereby cause outward radial movement of the jaws 25.

While the apparatus disclosed and describedherein constitutes a preferred form of the invention, yet it is understood that it is capable of mechanical alteration without departing from the spirit of the invention, and that all modifications that fall within the scope of the appended claims are intended to be included herein.

Having thus fully described my invention, what I clai-mas new and desire to secure by Letters Patent:

supporting thrust load of, said table, a ring gear for driving said table, bearing means co-axial with said spindle carried by said frame upon which said ring gear is journaled and supported independently of said table to thereby relieve said table of any supporting thrust load of said ring gear, means including a lost motion connection operably connecting said ring gear to drive said table, means for driving said ring gear, a brake drum fixed on the lower end of said spindle, a

brake band carried upon said frame and cooperating with said brake drum, and fluid actuated means on said frame for operating said brake band to engage said brake drum to arrest rotation of said table when said ring gear is being actuated by said ring gear drivin means to control the operation of said lost motion connection.

2. In a vertical boring mill, the combination of a frame, a rotatable table, spindle means projecting down from said table and journaled in bearing means in said frame to provide an axis of rotation for said table, bearing means carried by said frame for supporting the weight of said table and upon which it is rotated to thereby relieve'said spindle from the supporting thrust load of said table, a ring gear for driving said table, bearing means co-axial with said spindle carried by said frame upon which said ring gear is journaled and supported independently of said table to thereby relieve said table of any supporting thrust load of said ring gear, means operably connecting said ring gear with said table to drivingly inter-connect the same, means for driving said ring gear, a brake including a brake-band operatively connected to the lower end of said spindle, fluid actuated means for operating said brake-band, and a fluid pump carried by said frame for supplying fluid under pressure to said fluid operable means to actuate the same and thereby operate said brake-band to restrict rotation of said table in opposition to operation of said driving means for the ring gear to facilitate 1 the operation of said lost motion connection.

When the table 20 has stopped rotation, the

tool is retracted from the bore. The drive shaft 3. In a machine tool structure comprising a, frame, a table journaled forrotation about avertical axis on said frame, a spindle connected to 7 and depending downwardly from said work table, journal means for said spindle on said frame located below said table, driving means for said work table including a lost motion driving connection thereto, and braking means interconnectable between said spindle and said frame and located below said journal means for said spindle for arresting rotation in said work spindle during operation of said driving means to facilitate the operation of said lost motion driving connection.

4. In a machine tool structure comprising a frame, a table journaled for rotation about a vertical axis on said frame, a spindle connected to and depending downwardly from said work table, journal means for said spindle on said frame located below said table, driving means for said work table including a lost motion driving connection thereto, braking means interconnectable between said spindle and said frame and located below said journal means for said spindle for arresting rotation in said work spindle when power is connected to or disconnected from driving said table, and fluid pressure actuating means for said braking means mounted in said frame below said work table operable in conjunction with the operation of said driving means to facilitate the control of said lost motion connection.

5. In a machine holder supported on the frame of said machine, a spindle having one'end fixed to said work holder, a brake device including a brake drum flxed to the other end of said spindle, journal means on said frame for said spindle located intermediate said work holder and braking means, fluid pressure means on said frame for actuating said braking means, power means mounted on said frame for driving said work holder, and a lost motion connection between said power means and said work holder adapted to engage or release said work holder in response to the simultaneous operation of said power means and said brake.

6. In a vertical boring mill having a'horizontally rotatable work table journaled on a frame of said machine, chucking mechanism on said work table responsive to the direction of rotation of said table for clamping or unclamping a work piece relative to said table, power means for driving said work table including a lost motion connection to facilitate the operation of said chucking mechanism, a spindle connected to said work table and extending downwardly in a supporting journal in said frame, and braking means operabiy associated with the lower end of said spindle below said journal for arresting rotation of said work table during operation of said power means to cause said lost motion connection to clamp or unclamp said chucking mechanism.

7. In a, machine tool structure comprising a frame, a rotatable work spindle on said frame, chucking mechanism on said work spindle, power means for reversibly rotating said work spindle, and a chuck operating mechanism responsive to the direction of rotation of said work spindle including a lost motion driving-connection from said power means to said work spindle, and braking means operatively associated with said work spindle to arrest rotation of said spindle upon operation of said power means to engage or release said chucking mechanism relative to a work piece on said work spindle.

8. In a machine tool having a rotatable work spindle, a chuck on said spindle, power means tool having a rotatable work for driving said spindle, a, lost motion connection from said power means to the work engaging members of said chuck effective to drive said work spindle when a, work piece is gripped in said chuck and responsive to the direction of rotation of said power means for gripping or releasing said work piece in the chuck, and braking means operatively associated with said spindle to arrest rotation of said spindle so that operation of said power means causes said lostmotion connection to operate said chuck independent of the inertia of said spindle and a work piece in said chuck.

9, In a, vertical boring mill, a horizontally rotatable work table, including a work spindle journaled on the frame of said machine, a source of power for driving said table, a, chuck mounted on said table including work engaging jaws operable by the direction of application of driving power to said work table from a power source to engage or release a work piece in the chuck, a lost motion connection between said power source and said chuck responsive to change of direction of application of said power source, and braking means on said work spindle to arrest rotation of said work table to increase the effectiveness of actuation of said chuck jaws through said lost motion drive connection.

10. In a vertical boring mill, a horizontally disposed rotary work table journaled on the frame of said machine, a work spindle fixed to said work table and extending downwardly therefrom, journal means for said spindle in said frame below said table, a brake device operatively connectable to the lower end of said spindle below said journal means, chuck jaws radially reciprocatable on said table, power means, and a lost motion driving connection between said power means and said chuck jaws effective to drive said work table and spindle when a work piece is gripped by said chuck jaws by engagement of said brake, said lost motion driving connection being efiective to release said work piece from said chuck jaws upon engagement of said brake and reversal of said power means.

11; In a, machine tool structure including a horizontally rotatable work table, a work chuck on said table, power means for driving said table through a lost motion connection means interconnected with said work chuck, a spindle connected to said work table and extending downwardly therefrom, bearing means engaging said work table, said spindle, and said lost motion connection means below said work table, a brake device operatively connectable to said work spindle below said bearing means to arrest rotation of said work table to cause said lost motion connection to actuate said chuck upon operation of said power means, and means for supplying lubricant to said bearing means including an inlet supply connection adjacent said brake device and below said table, and 'fluid discharge means from said bearing means for return of fluid to a reservoir in said frame.

OTTO E. SCHURR.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,185,061 Clarke May 30, 1916 1,296,885 Wais Mar. 11, 1919 1,570,799 Trosch et al Jan. 26, 1926 

